Elevated anti-müllerian hormone concentrations in blood serum of dogs with oligozoospermia or azoospermia

Reduced semen quality such as oligozoospermia or azoospermia is a frequent reason for subfertility in dogs. Anti-Müllerian hormone (AMH), produced by Sertoli cells, is known to play a role in spermatogenesis. Elevated serum AMH concentrations have been reported in dogs with Deslorelin-induced testicular atrophy resulting in azoospermia. This led us to hypothesize that congenital or acquired oligozoospermia or azoospermia often due to testicular degeneration or atrophy may also result in increased AMH serum levels, and that AMH could potentially serve as a diagnostic marker. The study included 14 dogs diagnosed with oligo- or azoospermia and twenty-nine proven sires served as controls. All dogs underwent a physical and andrological examination, semen evaluation, and blood collection for serum AMH measurement. In the dogs with oligo- or azoospermia, a testicular ultrasound was undertaken, and in twelve serum testosterone was measured. Additionally, pathohistological examination following castration was carried out in four dogs, and in two of these, immunohistochemical analysis using anti-AMH antibodies was performed. Serum AMH concentrations in dogs with oligo- or azoospermia were significantly higher than in the control group (p < 0.001, power: 99.98 %), with no overlap in values. These results suggest that oligo- or azoospermia in dogs goes along with an increase in serum AMH concentration, comparable to other testicular disorders such as Sertoli cell tumors or cryptorchidism from which it has to be distinguished.